| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium secondary battery having a pressure actuation type current interrupt device, which is arranged to keep high overcharge resistance even after repetition of rapid charge and discharge.SOLUTION: A lithium secondary battery comprises: an electrode body having a positive electrode and a negative electrode, and a nonaqueous electrolytic solution containing a supporting electrolyte; and a battery case in which the electrode body and the nonaqueous electrolytic solution are enclosed. In addition to the supporting electrolyte, the nonaqueous electrolytic solution includes: 2 mass% or more of a gas generating agent which decomposes and generates gas when the battery is put in an overcharged condition; and 1 mass% or more of polyethylene glycol fatty acid ester serving as a surfactant. The battery case has a current interrupt device which is actuated in response to the rise in the pressure in the case. In a preferred embodiment, the content of the polyethylene glycol fatty acid ester is 3 mass% or less. Further, in another preferred embodiment, the content of the gas generating agent is 5 mass% or less. |
